SANTA CLARA - Few events in professional sports scream urgency much more than playing an elimination game on the road.

Perhaps the only thing that tops it starting out a win-or-go home game in a one-goal deficit.

And how about doing it against a team you haven't beaten in four previous tries?

That's what the Galaxy faced Wednesday going into the last of a two-game aggregate MLS Western Conference semifinals, ostensibly the second half of a 180-minute game after their 1-0 loss to San Jose on Sunday in Carson.

The Galaxy responded to that urgency with an inspired effort in a resounding 3-1 victory over top-seeded San Jose in front of 10,744 at Buck Shaw Stadium in Santa Clara.

The Galaxy scored all three of their goals in the first half.

"We wanted to come out right out of the gates. We knew they were probably going to sit in since they were up a goal," Galaxy defender Tommy Meyer said. "I knew that if we came in, got a couple of goals, that would put them on their heels."

The victory gave the Galaxy a 3-2 aggregate win in the series and sent the Galaxy to the two-leg conference final. They'll play host to the winner of today's aggregate playoff finale between No. 2 Real Salt Lake and No. 3 Seattle in Sunday's opener at 6 p.m. at Home Depot Center.

Considering their recent history, the Galaxy's response to desperate circumstances probably shouldn't be a total surprise. Last week, the No. 5-seeded Galaxy rallied for a 2-1 victory over No. 6 Vancouver in a play-in game.

Facing equally dire circumstances Wednesday, the Galaxy, who are seeking to become just the third team to win consecutive MLS titles, put together perhaps their best half of the season.

Robbie Keane scored two goals and Mike Magee scored another and had an assist to lead the Galaxy. Landon Donovan had two assists in the first half.

"Robbie's a great player," Galaxy coach Bruce Arena said. "Since he's come back from the European championships he's been the best player in the league.

"He scores big goals."

None were bigger than his first in the 21st minute. Keane dribbled the ball through a pack of San Jose defenders and scored into the corner of the goal past diving Earthquakes goalie Jon Busch.

Magee assisted on Keane's score, which set the tone for a team that was 0-3-1 against San Jose this season. The Galaxy also had leads in three regular-season meetings.

This time, Los Angeles didn't let up.

Keane threaded a shot into the corner of the net off an assist from Donovan in the 34th minute to make it 2-0. The Galaxy stretched their lead to 3-0 five minutes later when Magee punched in a shot from the middle of the penalty area off a sharp crossing pass from Donovan.

The Galaxy, however, wasted several early chances.

In the fourth minute, David Beckham's free kick from outside the penalty area sailed just over the corner of the Earthquakes net.

Two minutes later, Busch lunged to his right and punched away a Beckham free kick.

The Earthquakes broke through for their goal in the 82nd minute by Alan Gordon.

They earlier had a chance to cut into the lead in the 42nd minute, but Marvin Chavez's free kick bounced off the goal post.

The Galaxy were playing their third game in seven days and fourth game in 10 days.

"It's been challenging, but the way these guys have gone about their business is fabulous," Arena said. "Hopefully we can get them ready for the next series, which will be a tough one."